County profile · official public datasets

Davison County, SD

123 public highway bridges tracked in the FHWA National Bridge Inventory: 34.1% rated Good, 48.8% Fair, 17.1% Poor.

123
Public bridges: 34.1%
Good condition: 17.1%
Poor condition

The verdict

According to the Federal Highway Administration's 2024 National Bridge Inventory.

Davison County posts a higher-than-median Poor-condition share among rated counties in the state across mid-size county bridge inventory.

42nd
of 66 on Poor share: 17.1%
Poor-condition share: 123
public highway bridges: 1973
avg year built

Poor is an FHWA condition category from the lowest applicable component rating (4 or below), not a live crossing-safety or closure decision. Rankings cover counties with at least five public highway bridges.

Davison County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Davison County ranks #42 of 66 South Dakota counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 17.1%). Davison County, South Dakota contains 123 public highway bridges. Roughly 34.1% are rated “Good,” 48.8% “Fair,” and 17.1% “Poor.” Poor means the lowest applicable deck, superstructure, substructure, or culvert rating is 4 or below on the 0–9 NBI scale. It is a condition category, not a live safety or closure decision.

Responsible agencies inspect covered bridges on risk-based intervals under current NBIS rules and submit inventory data to FHWA annually. The list below shows every NBI-tracked bridge in the county. Use the “Sort by” controls to change the ordering, and click any row for its reported inspection date, traffic count, and condition fields.

Source: FHWA National Bridge Inventory. See methodology for full definitions.

Total bridges

123

Public highway bridges in Davison County

Good condition

34.1%

42 of 123 rated 7-9

Fair condition

48.8%

60 of 123 rated 5-6

Poor condition

17.1%

21 of 123 rated 4 or below

In-state Poor-share rank

#42 of 66

Among South Dakota counties with 5+ bridges, lower share ranks better

Condition distribution

Share of 123 NBI-tracked bridges by lowest applicable component rating.

Good

34.1% (42)

Fair

48.8% (60)

Poor

17.1% (21)

Davison County's Poor-condition bridges carry 1,728 vehicle crossings a day

That is 1.1% of the county's reported daily bridge traffic on 17.1% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 82 crossings a day against 1,429 for a Good-condition one. A Poor rating is a condition category, not a closure or a live safety judgement; it means the lowest applicable component rating is 4 or below.

Computed over the 123 of 123 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

54.5% of Davison County's bridges have passed the 50-year mark

67 of the 123 bridges with a recorded construction year were built in 1974 or earlier. Age alone is not a defect: a well-maintained older bridge can rate Good, and 34.1% of this county's inventory does. Even so, this older cohort is the population from which future Poor ratings are drawn, which is why the age profile below matters alongside the condition split above.

Cutoff derives from the 2024 release year minus a 50-year design life. Source: FHWA National Bridge Inventory, 2024 release.

One structure carries 22.6% of the county's Poor-condition bridge traffic

403RD AVENUE over FIRESTEEL CK, built 1910, carries 390 vehicles a day, the most of any Poor-rated structure here. The county's Poor-condition exposure is concentrated rather than evenly spread, so the 21-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 1,728 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1910s

4
1920s

6
1930s

8
1940s

8
1950s

3
1960s

30
1970s

18
1980s

9
1990s

8
2000s

19
2010s

4
2020s

6

What this shows Construction peaked in the 1960s, when 30 of the county's bridges still in the inventory were built, which is 24.4% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year (1973) matches the South Dakota average (1975).

How Davison County compares with South Dakota's closest counties by inventory size

The 5 South Dakota counties nearest Davison County in number of bridges, with their condition splits. Its 17.1% Poor share is the 4th-lowest of these 6. Its average build year of 1973 against a peer-group mean of 1971 is in line with the group.

Showing the 5 closest of 65 South Dakota counties eligible for comparison.

Bridge inventory size and condition shares for Davison County and the 5 South Dakota counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Butte County	143	30.8%	57.3%	11.9%	1976
Lawrence County	136	36%	51.5%	12.5%	1980
Bon Homme County	126	21.4%	50.8%	27.8%	1961
Hand County	126	24.6%	46%	29.4%	1961
Davison County (this page)	123	34.1%	48.8%	17.1%	1973
Lyman County	114	40.4%	50%	9.6%	1975

Each share is of that county's own total tracked bridges; peers are the counties with 5 or more bridges whose inventory size is closest to Davison County's. Source: FHWA National Bridge Inventory, 2024 release.

Nationwide counties with similar inventory size or average build year

Two NBI-derived peer sets for Davison County, both outside South Dakota so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside SD (123 bridges here).

Jackson County, GA · 123 bridges
Crawford County, IN · 123 bridges
Hickman County, KY · 123 bridges
Bladen County, NC · 123 bridges

Similar average build year

Nearest mean year-built outside SD (1973 here).

Jefferson County, AL · avg 1973 · 1,068 bridges
Erie County, NY · avg 1973 · 906 bridges
Davidson County, TN · avg 1973 · 832 bridges
Lancaster County, PA · avg 1973 · 801 bridges

Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.

All 123 Good 42 Fair 60 Poor 21

Fair-condition bridges (60)

Sort:

Davison County Bridge Snapshot

Condition distribution

Davison County's Poor-condition bridges carry 1,728 vehicle crossings a day

54.5% of Davison County's bridges have passed the 50-year mark

One structure carries 22.6% of the county's Poor-condition bridge traffic

How Davison County compares with South Dakota's closest counties by inventory size

Nationwide counties with similar inventory size or average build year

Similar inventory size

Similar average build year

Fair-condition bridges (60)

263RD STREET

259TH STREET

394TH AVENUE

396TH AVENUE

396TH AVENUE

397TH AVENUE

398TH AVENUE

248TH STREET

264TH SREET

402ND AVENUE

402ND AVENUE

245TH STREET

403RD AVENUE

261ST STREET

265TH STREET

404TH AVENUE

404TH AVENUE

404TH AVENUE

405TH AVENUE

405TH AVENUE

405TH AVENUE

405TH AVENUE

258TH STREET

265TH STREET

406TH AVENUE

406TH AVENUE

247TH STREET

407TH AVENUE

262ND STREET

408TH AVENUE

408TH AVENUE

408TH AVENUE

259TH STREET

409TH AVENUE

409TH AVENUE

409TH AVENUE

409TH AVENUE

245TH STREET

262ND STREET

262ND STREET

410TH AVENUE

SD037 S

S. MINNESOTA ST.

250TH STREET

SD037

I090 W

I090 E

401ST AVENUE

SANBORN ST (SD37)

FOSTER STREET

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